Vacuum tank introduction: The vacuum tank is independently developed by Fuguo Underwater World and is the first of its kind in my country. The upper layer of the fish tank is sealed and evacuated. Using the principle of negative pressure, the fish tank can be operated by an external switching device. When the water pump sends water into the tank, the air in the tank is pumped out to the outside by the operation of the suction device, causing the water level in the tank to rise. The feeding port is opened on one side of the fish tank, below On the water surface in the tank, when the feeder puts his hand into the feeding port to feed the fish, the water in the tank will not overflow. The length of the fish tank is 4 meters and the height is 1.5 meters. There are docile koi and crucian carp in the tank. Visitors can experience the feeling of a diver feeding the fish, put their hands into the tank to have close contact with the fish, and even pet them.